The present invention relates generally to engines, and more particularly to radial cam driven internal combustion engines.
Radial cam driven internal combustion engines have multiple cylinders located radially about a central drive shaft. The pistons operating inside the cylinders have connecting rods with rollers at one end that push against and thereby rotate a cam, as opposed to the connecting rods being attached to a crank pin and crankshaft. Radial cam driven engines have been plagued with problems related to side loading of the connecting rod due to the tangent force vector resulting from the angular contact of the connecting rod roller against the cam, especially during the power stroke (or combustion stroke). Also, especially in the area of light aircraft and Ultralight vehicles, the engines traditionally available produce excess noise, vibration and lack efficiency.
There is thus a need in the art for an efficient, quiet and smooth running radial cam driven engine that alleviates the tangential force resulting from the angular contact of the connecting rod roller against the cam.
The present invention advantageously addresses the needs above as well as other needs by providing an efficient, quiet and smooth running radial cam driven engine having connecting rods and connecting rod guide pins that alleviate the tangential force resulting from the angular contact of the connecting rod roller against the cam.
In one embodiment, the invention can be characterized as a radial cam driven internal combustion engine. The engine has a crankcase, a camshaft rotatably attached to the crankcase and a cam fixedly attached to the camshaft. A plurality of cylinders are located radially about the camshaft and are attached to the crankcase. A plurality of pistons are located within the cylinders and a plurality of connecting rods are each attached at a first end to an associated piston. At the second end of each connecting rod is a hollow area. Each connecting rod cam roller in a plurality of connecting rod cam rollers is rotatably attached to the second end of an associated connecting rod and is located against the cam. Also, a first end of each connecting rod guide pin in a plurality of connecting rod guide pins is located slidably inside the hollow area of an associated connecting rod. A second end of each connecting rod guide pin is fixedly attached to the crankcase.
In another embodiment, the invention can be characterized as an apparatus for use in a radial cam driven internal combustion engine comprising a connecting rod having a hollow portion in one end and a connecting rod guide pin located slidably inside the hollow area. The connecting rod guide pin is stationary and the connecting rod slides on it during operation.
In yet another embodiment, the invention can be characterized as a process of piston operation in an internal combustion engine comprising the steps of pushing a piston in a cylinder during a compression stroke with a cam of a cam driven internal combustion engine and dwelling the piston at top dead center long enough to substantially consume all fuel in the cylinder when ignited.
A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description of the invention and accompanying drawings which set forth an illustrative embodiment in which the principles of the invention are utilized.